% generate x and y coordinates.
x=linspace(0,2*pi,50);
y1=sin(x);
y2=cos(x);
y3=x.^2;
% plot a figure.
plot(x,y1,'Color','r','Marker','+','LineStyle',':');
hold on;
clf;
plot(x,y2,"g*-");
% hold;
figure;
plot(x,y3,"g*-");
% set the region of x and y axis
% axis([min(x)-2 max(x)+2 min(y)-10 max(y)+10]);
% set axis labels
xlabel('时间')
ylabel('温度')
% set the title of figure
title('时间-温度散点图')